- Supramolecular liquid crystals with hydrogen-bonding self-assembled T-shaped mesogens
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A new class of supramolecular liquid crystals with T-shaped mesogens are obtained by doubly hydrogen-bonded self-assembly of 2,6-bis(4-hexyloxybenzoylamino)pyridine and benzoic acid derivatives.
- Chen, Dongzhong,Wan, Lei,Fang, Jianglin,Yu, Xuehai
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- New chalcone based liquid crystals with allylidene amino linking unit: Synthesis and characterization
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In this study, the synthesis, structural characterization and mesomorphic properties of newly thirteen calamitic shaped compounds derived from allylidene amino chalcone and 4-n-alkoxy benzoyloxy benzoic acid. Comp.H1 to H3 exhibited nonliquid crystalline nature, while comp.H4 to comp.H18 displayed enantiotropical smectic C phase. Phase transition temperatures of present synthesised compounds were determined by optical polarising microscopy (POM), differential scanning calorimetric (DSC) and powder X-ray diffraction (PXRD) techniques. Thermal stabilities of smectic to isotropic phase are 150.0 °C and temperature range of mesophase is in decreasing order from comp.H3 to comp.H18 respectively. The presences of SmC phase are the type of broken fan and needle type in present synthesized series. It is also shown that presence of chalcone amino allylidene central linking group favors a calamitic liquid crystalline behaviour in molecules with lower member to higher member aliphatic side chain in alkoxy group (-OR).
- Sharma, Vinay S.,Sharma, Anuj S.,Jadeja, Upendra H.,Suthar, Deepak
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- New hockey stick shaped amino allylidene (?N?CH?CH?CH) based compounds: Effect of linkage group on mesomorphic properties
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Two nonlinear hockey stick shaped homologous series based on three linking groups have been synthesized and characterized by elemental analyses and spectroscopic techniques. The mesomorphic properties of these compounds were observed by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In this present investigation, we have synthesized two homologous series viz. 2-((3-phenyl allylidene) amino) phenyl 4-((4-n-alkoxy benzylidene) amino) benzoate (series-1) and 4-((2-((3-phenyl allylidene) amino) phenoxy) carbonyl) phenyl-4-n-alkoxy benzoate (series-2). Both the series are differing with respect to first linking group. In series-1, comp.C4-C18 shows nematic as well as smectic phase while in series-2, comp.C10-C16 shows smectic and nematic phase while comp.C4-C18 shows only nematic phase.
- Sharma, Vinay. S.,Vekariya, Rajesh. H.,Sharma, Anuj. S.,Patel
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- Synthesis and mesomorphic properties of calamitic shaped molecules with chalconyl-ester and lateral fluoro substituents
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In this study we have synthesized a new class of compounds incorporating of chalcones and laterally substituted fluoro group. A series of new chalcones with five aromatic rings is synthesized and characterised by elemental analyses and spectroscopic techniques such as Fourier transform infrared [FT-IR] and proton magnetic resonance magnetic resonance [1H NMR] spectroscopy. The mesomorphic properties of these compounds were observed by optical polarized light microscopy (POM) and confirmed by differential scanning calorimetry (DSC). It is found that all the prepared materials display enantiotropic LCs phases except first three homologue in present series. The lower homologues (n = 4 to 12) display SmC and nematic phase while, in higher homologues (n = 14 to 18) only SmC phase were seen in heating and cooling condition.
- Sharma, Vinay S.,Sharma, Anuj S.,Vekariya, Rajesh H.,Patel
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- 2,2'-Binaphthalene Ester Chiral Dopants for Cholesteric Liquid Crystal Displays
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A liquid crystal composition comprising a chiral dopant compound represented by the following structure (Structure 1): wherein: R1 and R2 are independently hydrogen, —(C═O)R9, —(C═O)R10, alkyl, aryl, alkaryl, alkenyl, cycloalkyl, alkoxyaryl, or heterocyclic all either substituted or unsubstituted, or combine to form a carbocyclic or heterocyclic ring; and R3-R9 are as described in the disclosure. Also featured are liquid crystal compositions comprising a chiral dopant compound represented by any of Structure 2-4 as described in the disclosure.
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(2014/03/24)
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- Tetraoxybiphenyl Ester Chiral Dopants for Cholesteric Liquid Crystal Displays
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A liquid crystal composition comprising a chiral dopant compound represented by the following formula: wherein: R1, R2 are independently aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl, alkaryl or heterocyclic all either substituted or unsubstituted, or combine to form a carbocyclic or heterocyclic ring; R3 and R4 are independently hydrogen, halogen, cyano, alkoxy, NHCOR7, NHSO2R7, COOR7, OCOR7, aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl, alkaryl or heterocyclic all either substituted or unsubstituted, or combine with either R1 or R2 to form a carbocylic or heterocyclic ring; R5 and R6 are independently hydrogen, CH2, CH, alkyl or aryl either substituted or unsubstituted, COOR7, or combine with L to form a carbocyclic or heterocyclic ring; R7 is aryl, alkyl, alkenyl, cycloalkyl, alkoxyaryl or heterocyclic all either substituted or unsubstituted; L is the non-metallic elements required to form a carbocyclic or heterocyclic ring, or a single bond or a double bond; m is 1-3; n is 0-12.
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Page/Page column 18
(2012/11/08)
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- THERMOTROPIC LIQUID CRYSTAL BEHAVIOR IN SOME AROMATIC ESTERAMIDES.
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Ester-amide analogs of p-phenylene di-p-substituted benzoates have been synthesized and the thermotropic liquid crystal properties of the two series are compared. The crystalline, smectic, and nematic phases are all more thermally stable in the ester-amides than in the diesters. In the corresponding series of 4-alkoxybenzoyl compounds, as the alkyl chain length increases the difference in nematic phase stability also increases, but the difference in smectic phase stability decreases. Introduction of a methyl substituent into the central ring reduces the stability of all three phases, and increases the sensitivity of smectic phase stability, but not of crystalline or nematic phase stability, to alkyl chain length.
- Kalyvas,McIntyre
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p. 105 - 118
(2007/10/02)
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